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Seidel Test
The Seidel test is used to assess the presence of aqueous humor leakage from Anterior chamber of eyeball, anterior chamber of the eye. Leakage may occur due to many corneal or scleral disorders, including corneal post-trauma, post-surgical leak, corneal perforation and corneal degeneration. Initially the test was used to detect aqueous humor leakage in postoperative patients, later it expanded to detect other causes or anterior chamber leakage. Name The Seidel test was first described by German ophthalmologist Erich Seidel (ophthalmologist), Erich Seidel in 1921. Procedure A fluorescein strip containing 10% fluorescein is applied topically to the affected area, without applying pressure on the eye due to the risk of tissue extrusion. The fluorescein is examined with a cobalt blue filter. At this point, the fluorescein appears green in color. Any changes in color or surface of the fluorescence area indicate the presence of corneal leakage. The test is contraindicated in obvious ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aqueous Humor
The aqueous humour is a transparent water-like fluid similar to plasma, but containing low protein concentrations. It is secreted from the ciliary body, a structure supporting the lens of the eyeball. It fills both the anterior and the posterior chambers of the eye, and is not to be confused with the vitreous humour, which is located in the space between the lens and the retina, also known as the posterior cavity or vitreous chamber. Blood cannot normally enter the eyeball. Structure Composition *Amino acids: transported by ciliary muscles *98% water *Electrolytes ( pH = 7.4 -one source gives 7.1) **Sodium = 142.09 **Potassium = 2.2 - 4.0 **Calcium = 1.8 **Magnesium = 1.1 **Chloride = 131.6 **HCO3- = 20.15 **Phosphate = 0.62 ** Osm = 304 *Ascorbic acid * Glutathione * Immunoglobulins Function *Maintains the intraocular pressure and inflates the globe of the eye. It is this hydrostatic pressure that keeps the eyeball in a roughly spherical shape and keeps the walls of the e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anterior Chamber Of Eyeball
The anterior chamber ( AC) is the aqueous humor-filled space inside the eye between the iris and the cornea's innermost surface, the endothelium. Hyphema, anterior uveitis and glaucoma are three main pathologies in this area. In hyphema, blood fills the anterior chamber as a result of a hemorrhage, most commonly after a blunt eye injury. Anterior uveitis is an inflammatory process affecting the iris and ciliary body, with resulting inflammatory signs in the anterior chamber. In glaucoma, blockage of the trabecular meshwork prevents the normal outflow of aqueous humour, resulting in increased intraocular pressure, progressive damage to the optic nerve head, and eventually blindness. The depth of the anterior chamber of the eye varies between 1.5 and 4.0 mm, averaging 3.0 mm. It tends to become shallower at older age and in eyes with hypermetropia (far sightedness). As depth decreases below 2.5 mm, the risk for angle closure glaucoma increases. Clinical significan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cornea
The cornea is the transparent front part of the eye that covers the iris, pupil, and anterior chamber. Along with the anterior chamber and lens, the cornea refracts light, accounting for approximately two-thirds of the eye's total optical power. In humans, the refractive power of the cornea is approximately 43 dioptres. The cornea can be reshaped by surgical procedures such as LASIK. While the cornea contributes most of the eye's focusing power, its focus is fixed. Accommodation (the refocusing of light to better view near objects) is accomplished by changing the geometry of the lens. Medical terms related to the cornea often start with the prefix "'' kerat-''" from the Greek word κέρας, ''horn''. Structure The cornea has unmyelinated nerve endings sensitive to touch, temperature and chemicals; a touch of the cornea causes an involuntary reflex to close the eyelid. Because transparency is of prime importance, the healthy cornea does not have or need blood ve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sclera
The sclera, also known as the white of the eye or, in older literature, as the tunica albuginea oculi, is the opaque, fibrous, protective, outer layer of the human eye containing mainly collagen and some crucial elastic fiber. In humans, and some other vertebrates, the whole sclera is white, contrasting with the coloured iris, but in most mammals, the visible part of the sclera matches the colour of the iris, so the white part does not normally show while other vertebrates have distinct colors for both of them. In the development of the embryo, the sclera is derived from the neural crest. In children, it is thinner and shows some of the underlying pigment, appearing slightly blue. In the elderly, fatty deposits on the sclera can make it appear slightly yellow. People with dark skin can have naturally darkened sclerae, the result of melanin pigmentation. The human eye is relatively rare for having a pale sclera (relative to the iris). This makes it easier for one individual t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Corneal Perforation
Corneal perforation is an anomaly in the cornea resulting from damage to the corneal surface. A corneal perforation means that the cornea has been penetrated, thus leaving the cornea damaged. The cornea is a clear part of the eye which controls and focuses the entry of light into the eye. Damage to the cornea due to corneal perforation can cause decreased visual acuity. Signs and symptoms Corneal perforation may cause difficulty in seeing and persistent eye pain. Physical examination In a physical examination, medical examination, or clinical examination, a medical practitioner examines a patient for any possible medical signs or symptoms of a medical condition. It generally consists of a series of questions about the pati ... may reveal discoloration of the cornea. Causes Perforation of the cornea may occur due to diseases of the cornea, injury during eye surgery, or infection of the eye, which may occur after surgery or procedures. Pellucid marginal degeneration may c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ophthalmologist
Ophthalmology ( ) is a surgical subspecialty within medicine that deals with the diagnosis and treatment of eye disorders. An ophthalmologist is a physician who undergoes subspecialty training in medical and surgical eye care. Following a medical degree, a doctor specialising in ophthalmology must pursue additional postgraduate residency training specific to that field. This may include a one-year integrated internship that involves more general medical training in other fields such as internal medicine or general surgery. Following residency, additional specialty training (or fellowship) may be sought in a particular aspect of eye pathology. Ophthalmologists prescribe medications to treat eye diseases, implement laser therapy, and perform surgery when needed. Ophthalmologists provide both primary and specialty eye care - medical and surgical. Most ophthalmologists participate in academic research on eye diseases at some point in their training and many include research as p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Erich Seidel (ophthalmologist)
Erich Seidel (1882–1946) was a German ophthalmologist known for his studies in the field of glaucoma, ocular anesthesia and aqueous humor dynamics. Seidel test and Seidel's scotoma are named after him. Biography Erich Seidel was born on 1882 December 30 at Apolda, Thüringen, Germany. He received MD from Jena in 1907 (Topic: über die Lidbildung mittels übertragener stiellser Hautlappen (eyelid formation by means of transferred skin flaps)). After specialising in Ophthalmology during 1907-1910, he began working as an assistant at the University of Heidelberg Eye Clinic in 1910 and was appointed Head Physician in 1916 and Ausserordentlicher Professor in 1919. In 1935 he was offered to join at the University of Gottingen, but he rejected. Receiving habitation in Heidelberg in 1914, his inaugural address was on the problems of spectacle glasses and solutions through modern spectacle optics. He spent his last days in Jene, East Germany. He died on February 26, 1946. Scientif ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fluorescein
Fluorescein is an organic compound and dye based on the xanthene tricyclic structural motif, formally belonging to triarylmethine dyes family. It is available as a dark orange/red powder slightly soluble in water and alcohol. It is widely used as a fluorescent tracer for many applications. The color of its aqueous solutions is green by reflection and orange by transmission (its spectral properties are dependent on pH of the solution), as can be noticed in bubble levels, for example, in which fluorescein is added as a colorant to the alcohol filling the tube in order to increase the visibility of the air bubble contained within (thus enhancing the precision of the instrument). More concentrated solutions of fluorescein can even appear red (because under these conditions nearly all incident emission is re-absorbed by the solution). It is on the World Health Organization's List of Essential Medicines. Uses Fluorescein sodium, the sodium salt of fluorescein, is used extensivel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cobalt Blue
Cobalt blue is a blue pigment made by sintering cobalt(II) oxide with aluminum(III) oxide (alumina) at 1200 °C. Chemically, cobalt blue pigment is cobalt(II) oxide-aluminium oxide, or cobalt(II) aluminate, CoAl2O4. Cobalt blue is lighter and less intense than the (iron-cyanide based) pigment Prussian blue. It is extremely stable and historically has been used as a coloring agent in ceramics (especially Chinese porcelain), jewelry, and paint. Transparent glasses are tinted with the silica-based cobalt pigment smalt. Historical uses and production Cobalt blue in impure forms had long been used in Chinese porcelain. The first recorded use of ''cobalt blue'' as a color name in English was in 1777. It was independently discovered as a pure alumina-based pigment by Louis Jacques Thénard in 1802. Commercial production began in France in 1807. The leading world manufacturer of cobalt blue in the nineteenth century was Benjamin Wegner's Norwegian company Blaafarveværket ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
